Remote control system



P. H. 'CRAGO REMOTE CONTROL SYSTEM 2 Sheets-Sheet '1 Filed Feb. 23,1933

INvENTOR Spt. 25, 1934.

Sept. 25, 1934 P. H. CRAGO ,4

REMOTE CONTROL SYSTEM Fiied Feb. 23, 1935 2 Sheets-Sheet 2 Em rj mw 3% IV INVENTOR Paalfl Cmzga QRW' 1115' ATTORNEY Patented Sept. 25, 1934 PATNT OFFICE REMOTE CONTROL SYSTEM Paul H. Crago, Wilkinsburg, Pa.,assignor to The UlllOn Switch &' Signal Company, Swissvale,

lla., a corporation of Pennsylvania Application February 2 s, 1933,Serial No. 658,066 16Claims (01. 246-3) My invention relates to remotecontrol systems; and particularly to remote controlsystems forcontrolling railway switches from a remote point and for communicatingto said re-, .mote point the position of said switches and otherinformation, such for example, as the posi-v tion of trains in ,thevicinity of the railway,

switches. t

In my copending application, Serial 151056311141, jfiled August 30,1932,'for Remote control systems, I have described a system of controlwherewith a two-way control is accomplished between two remotely locatedstations over a single pair of line wires. The control is efiected byproviding "a pair of loop circuits at each of the two stations, eachloop circuit being adapted to pass current in a given direction only;and by supplying impulses of current of opposite polarity to the linecircuit at time spaced intervals to selec-i In this 00-- tivelyinfluence these loop circuits.

pending application,- the specification describes apparatus forgoverning the operation of a single railway switch and its relatedsignals. The control of the railway switch from one extreme posijtion tothe'other position is effected by supplying current to the line circuitforonly a short predeterminedinterval, namely, during the release periodof a slow release relay. This slow release relay is governed by a pushbutton, and fthe arrangement is such that for each operationof thepushbutton, therailway switch is operated to the position opposite thatwhich it occupied just previous to the-operating of the'push button. Afeature ofmy present invention is the provision of novel and-,- improvedapparatus wherewith'the same general principle of control of my formercase isadapted togovern theoperation of at least three railway switches;and to indicate thepositions of'these switches over a single pair ofline wires, the line circuit being also available for OS-ing theoccupancy'of a'plurality oi different .track sections located inthevicinity of the switches. The utility of-thearrangement here disclosedis that a material-saving in linewires is'efiected. when several railwayswitches are to be controlled from the sameoilicestation, and the.occupancy of a number of different track sections isto be indicated. at

the remote ofiice station." Other features of my invention. will appearasthe specification pro- I willdescribe one form of apparatusembodyingmy invention, and will then point outthe novel features thereofinclaims.

In the accompanying drawings, Figs. 1 and 2,

when taken together, with Fig. 1 at the left, constitute a diagrammaticview of one form of apparatus embodying my invention for control-. lingthe operation of three railway switches; and for OS-ing the occupancy oftwo track circuits. The apparatus of Fig. 1 is thatlocated at the remoteor ofiice station, and the apparatus of Fig. 2 is that located at thefield station. While many different arrangements of railway switches towhich my present invention may be applied will naturally suggestthemselves to those skilled in the art, the specific arrangement heredisclosed is that of two derailing switches and one single switch at agrade crossing of two railways, each railway being equipped with a trackcircuit.

To simplify the drawings as much as possible, I have, in many instances,illustrated a circuit controlling contact remote from the relay windinggoverning the operation of that contact. In all such instances, thereference character corresponding to the controlling relay is placedjust above the contact, and the contact is further given a distinctive.individual reference character. The contact is illustrated in thedrawings in a position corresponding to the normal position of therelay. For example, the circuit' controlling contact of Fig. 2designated by' the reference character 20 is governed bya track relay6TB. to be referred to later, and this'front contact is shown closed,inasmuch as the track. relay -6TR is normally energized.

In the present application, only the control relays for governingtheoperation of each railway switch are shownjthe operating mechanism andoperating circuits being omittedas they form no part of my present.invention, For clarity, these control relays are each here designated bya reference character which corresponds to the reference character forthe same relay in my aforementioned application, a prefix being added inthis instance, however, to designate the associated switch. For acompleterunderstanding of the switch operating circuits, and the mannerin which the control relays governthe operating circuitsof a railwayswitch, reference is made to my copending application SerialNo'.631,041. It is deemed, therefore, suiiicientffor the present descriptionto point out specifically'the manner of selecting the control relays.for ,each 'particular switch from the remote office; and then refer onlyin a' general way to the manner in which 1 these control relaysfunctionto bring about the operation of the corresponding railwayswitch. Furthermore, in the present instance, no wayside signals areshown for governing trafiic inasmuch as the control of the Waysidesignals forms no part of my present invention. The wayside signals maybe of any of the standard types, and

may be automatically controlled; or they may be 5 controlled by thedispatcher at the remote ofiice by any one of several well knownsystems.

Referring to Fig. 2, the reference characters X and Y designate tworailway tracks crossing at grade. The railway X includes two derailin mswitches 6 and '7, and a single switch 9 leading to a side track Z. Thederailing switches 6 and 7 and the single switch 9 are each operated bya power operating switch mechanism of any one of several types, andwhich are shown on the drawings only by a symbol commonly used in theart for such purposes. The mechanisms for the switches 6, '7 and 9 aredesignated by the reference characters 6M, 7M and 9M, respectively.

As previously stated, the operating circuits for 2 governing each ofthese switch mechanisms 6M,

7M and 9M are preferably controlled by three switch controlling relaysin the manner described in detail in my copending application, SerialNo.

631,041. In Fig. 2, the operating mechanism 6M 5 is governed by thethree control relays SWR,

SRWR, and BNWR; ,the mechanism TM is controlled by the relays 'IWR, TRWRand 'YNWR;

and in like manner the mechanism 9M is con- 1 trolled by relays 9WR,QRWR and QNWR. In each of these groups of control relays, the WR relayis, preferably a polarized relay of the type in'which the polar armaturewhen the relay is deenergized, remains firmly held in the position towhich it was last moved when the relay was energized; and the RWR andthe NWR relays are preferably neutral relays. As illustrated in thedrawings, all three relays of a group are normally deenergized.

Referring to the group of control relays for the switch mechanism 6M,the relays GRWR and GNWR are governed by two dispatcher controlledrelays LGR and RGR to be later described, the relay GNWR being selectedover the normal, or lefthand position of a polar armature 21 of relayawn, and the relay GRWR being selected over the reverse orrighthandposition of the polar armature 21. When the dispatcher controlled relayLGR is picked up in a manner to be later described, current is suppliedfrom the B terminal of a battery 22 over back contact 23 of relay RGR,front contact 24 of relay LGR, normal position of polar armature 21,winding of relay GNWR and to a center C terminal of battery 22. In theevent polar armature 21 of relay GWR is in the reverse position, thepicking up of the dispatcher controlled relay LGR supplies current tothe relay 6RWR over this same circuit. As described in detail in myabove-mentioned copending application, relay SNWR when selected,completes a circuit which is adapted to supply to the winding of relay6WR current of a polarity that causes that relay to be energized in itsreverse position; and relay GWR when energized in its reverse position,causes the switch mechanism 6M to operate the switch 6 to its reverseposition. When the relay 6RWR is selected, it completes a circuit whichis adapted to supply to the winding of relay SWR cur- ,;-rent of apolarity that causes that relay to be energized in its normal position;and relay 6WR when energized in its normal position, in turn, causes themechanism GM to move the switch 6 to its normal position. While only theessen- -tial partsof the pickup circuits for the SN W R "and GRWR relaysare shown, it will be understood that the complete circuit for each NWRand RWR relay in connection with the associated WR relay will be thesame as shown in my copending application Serial No. 631,041; and hence,the energizing of either relay 6RWR or SNWR for only a brief interval issumcient to bring about a full corresponding operation of switch 6.

The relays 'YRWR and 7NWR of the control group for switch mechanism 7Mare also governed by the dispatcher controlled relays LGR and RGR. Inthis instance, the energizing of the relay RGR supplies current from theB terminal of battery 22 over the front contact 30 of relay RGR, backcontact 31 of relay LGR, winding of relay '7NWR when the polar armature32 of relay lWR occupies its normal position and thence to the Cterminal of battery 22, or to the winding of relay ZRWR when the polararmature 32 oocupies its reverse position and thence to the C terminalof battery 22. Selecting relay 'lNWR, completes a circuit for supplyingcurrent of reverse polarity to the relay 7WR, and that relay isenergized in its reverse position to cause the switch mechanism- FM tooperate the switch 7 to its reverse position. Selecting the relay 'YRWRcompletes a circuit for energizing the relay 'TWR in its normal positionto bring about a normal operation of the switch 7.

The relays QRWR and 9NWR, of the control group for mechanism 9M are alsogoverned by the dispatcher controlled relays LGR and RGR, the circuit inthis instance extending from the B terminal of battery 22, over frontcontact 30 of relay RGR, front contact 38 of relay LGR, and to thewinding of relay QNWR in the event the polar armature 39 of relay 9WRoccupies its normal position; and to the winding of relay QRWR in theevent the polar armature 39 occupies its reverse position as will bereadily understood by an inspection of Fig. 2. Selecting relay 9NWR.completes a circuit for energizing the relay 9WR in its reverse positionto move the switch 9 to its reverse position, and the selecting of relay9RWR, completes a circuit for energizing relay 9WR in its normalposition to bring about a normal operation of switch 9. It follows thatenergizing the dispatcher controlled relay LGR for an interval selectsthe group of control relays for the switch mechanism 6M and these relaysfunction to bring about an operation of switch 6; energizing thedispatcher controlled relay RGR for an interval selects the group ofcontrol relays for the switch mechanism 7M and these relays function tobring about an operation of the switch '7; and energizing both relaysLGR and. RGR for an interval selects the group of control relays formechanism 9M and these relays function to bring about an operation ofthe switch 9.

Operatively connected with the derailing switch 6 is a set of circuitcontrolling contacts 25, 26, 27 and 28. These contacts control apolarized switch controlled relay GKR, the circuit including a polararmature 29 of the switch controlling relay 6WR. In the normal positionof the switch 6, current is supplied from the B terminal of battery 22over contact 28, normal position of polar armature 29, winding of relayGKR and contact 27 to the opposite terminal N of battery 22. When theswitch 6 is reversed, contacts 25, 26, 27 and 28 are reversed; and thecircuit for the relay GKR extends from the B terminal of battery 22 overcontact 25, winding of relay 6KR, reverse position of polar armature 29,and contact 26 to the opposite terminal N of battery 22. 15c

r normal position. -Assum ing Thus, the switch controlled relay GKR isenergized with one polarity of current when the switch is normal, and isenergized with current of the reverse polarity when the switch 6 is setin its reverse position, agreement being required between the positionof the polar armature 29 of the switch controlling relay GWR and thecontactsoperated by the switch 6. A similar set of contacts 33, 34, 35and 36 is operatively connected with the derailing switch '7, and thisset of contacts together with a polar armature 3'!- of the switchcontrolling relay 'IWR govern an associated switch controlled relay 'YKRin the same manner as just described for relay GKR. That is to say, withswitch '7 set in its normal po sition, and polar armature 3'? in itsnormal position, relay 'TKR-is energized with current of one polarity;and when the switch '7 is set in its reverse position and polar armature3'7 is reversed, the relay TKRis energized with current of the reversepolarity. A set of contacts 40, 41,42 and 43 is operatively connectedwith the switch 9; and this set of contacts together with the polararmature 44 of relay QWR govern the operation of a switch controlledrelay QKR as will be readilyunderstood by an inspection of Fig. 2.

The railway track X includes a track section GT, and the railway track Yincludes a track section 8T. Track section 6T'and the track sec- -tion8T are each provided with the'usual track circuit, which includes abattery 5 connected across the rails at one end of the section and atrack relay R with a prefix corresponding to the M track section,connected across therails at the 35 opposite end of the section.

Referring now to Fig. 1, provided with three spring return push buttonsdesignated by-the reference characters 6PB, '7PB and 9P3, and thesepushbuttons govern the operation of switches 6, '7 and 9, respectively.As-

sociated wtih each push button are two control relays PBR and PBS, andtwo indicating relays NKP and RKP, a prefix corresponding to theassociated push button being added'in each case. The control relays PBRand PBS are-each slow releasing in character, and the indicating relaysNKP and BK? are each provided with two windings as will shortly bedescribed.

Each push button controls its associated control relays in the followingmanner. Depressing push button SP3, for example, completes an energizingcircuit for both its associated control relays'fSPBR and GPBS. Thecircuit for relay GPBR extends from the B terminal of a-battery 45,through back contacts 46 and 47 ofrelays {308R and 808R, respectively,and which relays will be later described, wire 53-, back contacts 50 and51 of relays QPBS and TEES, respectively, contact 41.8 of push button6Pl3,winding of relay SPBR,

and to a center terminal C of the battery 45.

The circuit for the relay SPBS is the same as just traced up to the backcontact 51 of relay 7PBS,

andthence over contact 49 of push button 6PB, windingof relay GPBS, andto the center 0 terminal of battery 45.

Thus, depressing the push button SPB causes both the control relays GPBRand GPBS to become energized, providing the stick relays 71 38 and QPBSfor the push buttons 'IPB and SP3, respectively, are deenergized, andproviding the. two relays 603R and 808R are also deenergized. Relay SEESis provided with a stick circuit for retaining that relay energizedafter the push button 6P3 has been restored to its the two indicatingrelays GNKP and GRKP to both be deenergized the oiiice station is itsown front contact '72,.

that the push button SP3 is ineffective to pick in a manner to laterappear, the stick circuit for relayfiPBS can be traced from the Bterminal of battery 45, back contacts 54 and 55 of relays 6NKP and SRKP,respectively, front contact 56, winding of relay 6PBS, and to the Cterminal of battery'45. It follows that when push button 6PB is releasedafter it has once been depressed, currentis cut off from the controlrelay GPBR, and that relay releasesat the end of a slow release period,but the stick relay 6PBS will remain energized over its stick circuit aslong as the associated indicating relays are both deen' ergized.

Referring now to push button 'IPB, this push button controls theenergizing of its control relays 7PBR and 'IPBS in a manner similar tothat just described for the push button 6PB. The energizing circuit forrelay 'YPBR extends. from the B terminal of battery 45 over backcontacts 46 and 47', wire 52, back contacts 58 and 59 of the opposingstick relays 6PBS and 9PBS, respectively, contact 60 of push button'lPB, winding of 'relay PIPER, and to the center C terminal of battery45; while the circuit for the relay 'ZPBS is the same as that justtraced up to the back contact. 59 of relay 9PBS, and thence throughcontact 57 of push button '7PB, winding of relay 'YPBS, and to thecenter C terminal of battery 45. Although'the control relay 7PBR has itscircuit opened when the push button 71 13 is restored to its normalposition and hence releases at the end of its slow release period; thestick relay 7PBS is-retained energized over a stick circuit easilytraced, and which includes the back contacts 64 and 65 of the associatedindicating relays lNKP and 'YRKP, respectively, andjits own frontcontact 63. It is to be noted that operating the push button 'IPB isineffective to energize its control relays unless the stick relays GPBSand QPBS for the other two push buttons SP3 and 9PB, and the relays 608Rand 808R are all deenergized.

In like manner, the push button 9PB controls the energizing of itscontrol relays QPBR and QPBS, the circuit branching from the wire 52along wire '71, back contacts 68 and 69 of the opposing stick relays'IPBS and SPBS, respectively, contact 70' of push button 9PB, winding ofrelay QPBR, and to the C terminal of battery 45; and through the contact66 of push button 9P3, winding of relay QPBS, and to the C terminal ofbattery 45. Returning the push button QPB to its normal position will atonce cut off current from the control relay 9PBR, and that relayreleases at the end of the slow release period, but the stick relay QPBSwill be now 'retained energized by a stick circuit which includestheback contacts 73' and 740i theassociated indicating relays QNKP and9RKP,-respectively, and Again, it is to be noted up its control relaysunlessthe stick relays 71938 and BPBS of the other two push buttons SP5and EB, and relays GOSH and 8OSR are all deenergized. It .is'clear fromthe foregoing that operating any one of the push buttons GPB, 'lPB orQPBre'sults in theenergization of the associated control relays, andthat the associated stick relay is retained energized after the pushbutton has been restored to its normal position as long as theassociated indicating relays are deenergized. The energized condition ofthe stick relay renders each of the remaining push buttons ineffectiveto pick up its associated control relays.

The officestation of Fig. l is connected with the field station of Fig.2 by a pair of line wires designated by the reference characters L andCom, the line Wire Com being connected directly to the center C terminalof both the batteries 45 and 22; and the line wire L being connected toeither the B or the N terminal of these two batteries 45 and 22 inaccordance with the condition of the apparatus at the office station andat the field station as will now be described. Depressing push button 6113 and the subsequent energization of the control relays GPBR and 6PBSconnects the B terminal of battery 45 with the line wire Lover frontcontact of relay GPBR, back contacts '16 and '7'! of the opposing stickrelays PBS and QPBS, respectively, and front contact 78 of theassociated stick relay GPBS. In the event the push button 71 B isoperated and its control relays 'ZPBR and 'ZPBS are subsequentlyenergized, the N terminal of battery 45 is connected with the line wireL over front contact 79 of relay 'YPBR, back contacts 80 and 81 of theopposing stick relays SPBS and 9PBS, respectively, and the front contact82 of the associated stick relay 'ZPBS. In case the push button QPB isoperated and itsassociated control relays QPBR and QPBS are subsequentlyenergized, two relays 83 and 84 are operated to alternateiy connect theB and the N terminals of battery 45 to the line wire L. Relay QPBR whenpicked up closes a front contact 35, and current flows from the Bterminal of battery 15 over front contact 85, back contact 86 of relay84, winding of relay 83, and to the terminal C of battery 45. Relay 83on picking up, closes its front contact 87 and current is supplied tothe winding of relay 84 by a simple circuit that includes the frontcontacts 85 and 87. Relay 84 in picking up opens the back contact 86removing current from the relay 83, and that relay releases to in turnopen its front contact 87 removing current from the relay 84. These tworelays 83 and 84 thus alternately pick up and release as long as thefront contact 85 of the relay 9PBR remains closed, each relaycontrolling the connection to the other. During each interval that relay83 is picked up, the N terminal of battery 45 is connected with the linewire L over front contact 88, front contact 89 of relay QPBR, backcontacts 90 and 91 of the opposing stick relays GPBS and 'YPBS,respectively, and the front contact 92 of the associated stick relaySPBS. During each in erval the relay 83 is deenergized, the B terminalof battery 45 connected with the line wire L over front contact 85, backcontact 93, and thence the same as previously traced.

It is clear from the foregoing description that operating the pushbutton 61 B causes-an impulse of current of positive polarity to besupplied to the line circuit the duration of which is equal to theinterval the push button 6PB is held down plus the slow release periodof the relay GPBR. When the push button 'ZPB is oper-" ated, an impulseof current of negative polarity is supplied to the line circuit, theduration of which is equal to the interval the push button '7PB is helddown plus the slow release period of the relay 'TPBR. Operating the pushbutton 9PB causes impulses of current alternately positive and negativein polarity, to be supplied to the line circuit during the slow releaseperiod of the control relay QPBPJ. In each instance, the associated.stick relay renders each of the other two push buttons ineffective tooperate its control relays.

Referring again to Fig. 2, the dispatcher controlled relays LGR and RGReach have one terminal of its winding connected directly to the commonline wire Com at the C terminal of battery 22. The opposite terminal ofthe winding of relay LGR is connected with the line wire L through acircuit network which can be traced from the line wire L over frontcontact 20 of the track relay 6TB, front contact 94 of the track relay8TH, back contacts 95, 96 and 9'7 of the switch controlling relays GWR,'YWR and QWR, respectively, wire 98, and a half-wave rectifier 99. Theopposite terminal of the winding of the relay RGR is connected to theline wire L through this same circuit network up to wire 98 and thencethrough a half-wave rectifier 100. The rectifiers 99 and 100 arearranged with their low resistance or forward direction reversed to eachother and are so positioned that when current of positive polarity isapplied to the line circuit, the relay LGR is energized, and when thecurrent supplied to the line circuit is of negative polarity, the relayRGR is energized. When impulses of current alternate in polarity flow inthe line circuit then both relays LGR and RGR, are energized, halfwaverectifiers 101 and 102 being connected across the windings of the relaysLGR and RGR, respectively, to make these relays slightly slow releasing.Consequently, when push button GPB is operated and an impulse of currentof positive polarity is supplied to the line circuit, the relay LGP; atthe field station is selected and the control relays GWR, SRWR. and GNWRare operated to effect an operation of switch 6. Depressing the pushbutton 71 B and the consequent supplying of an impulse of current ofnegative polarity to the line circuit, selects the relay RGR at thefield station and the control relays 'TWR, 'ZRWR and '7NWR are operatedto effect a movement of the switch 7. Actuating the push button 91 3results in impulses of current alternate in polarity being supplied tothe line circuit and both relays LGR and RGR are picked up to operatethe control relays for the switch mechanism 9M to bring about anoperation of the switch 9. In each instance the picking up of theassociated stick relay as a push button is operated renders the othertwo push buttons ineffective.

The manner 'of indicating the position of switches 6, 7 and 9 will nowbe taken up. As previously pointed out, each push button is providedwith a normal indicating relay NKP and a reverse indicating relay RKP.These indicating relays are of the double windin type, one winding beingincluded in a pick-up circuit for receiving an impulse from the linecircuit, and the second winding being included in a local stick circuitfor retaining the relay energized after an indication impulse has beenreceived. Referring to the relays GNKP and. GRKP for the push button6PB, these relays each have one terminal of their pickup or top windingconnected. directly to the common line wire at the C terminal of thebattery 45. The other terminal of the top winding of relay 6NKP isconnected with the line wire L over a loop circuit including a half-waverectifier 103, back contact 104 of relay GPBR, back contacts '76 and 7'7of the stick relays IPBS and 9 PBS, respectively ,and front contact 78of the stick relay GPBS. The other terminal of the top winding of relaySRKP is connected with the line wire L over a loop circuit including ahalf-wave rectifier 105, back contact 104, and thence over the samecircuit just traced for relay SNKP. The rectifier 103 is so positionedas to pass current flowing from the line wire L toward the common linewire Com, and to substantially block the flow of current in the oppositedirection, and the recti fier 105 is so positioned as to pass currentflowing from the common line wire Com toward the line wire L and tosubstantially block the flow of current in the opposite direction. Itfollows that at such time as the stick relay GPBS is picked up to closeits front contact 78 andthe control relay GPBR is down to close its backcontact104, an impulse of current of one polarity will pass through therectifier 103 to energize the relay GNKP, and an impulse of current'ofthe opposite polarity will pass through the rectifier 105 toenergize therelay SR-KP. In other words, as soon as the control relay fiPBR isreleased to terminate an outgoing control impulse, the two loop circuitsincluding the indicating relays SNKP and GRKP, respectively, areconnected with the line circuit, one loop circuit being so arranged asto respond to current of one polarity and the other loop circuit beingso arranged as to respond to current of the opposite polarity. Once therelay GNKP is picked up, it will be retained energized by virtue of astick circuit extending from the B terminal of the battery 45 over theback contact 106 of relay GPBR, its own front contact 107, and the loweror stick winding to the C terminal of battery 45. In like-manner, therelay fiRKP-once picked up, it will be retained energized by a stickcircuit extending from the B terminal or" battery 15 over back contact106, its own front contact 108, and its lower winding to the C terminalof the battery 45. Relay GNKP controls at its front contact 109 a simplecircuit for a normal indicating device 6N, and the relay SRKP controlsat its front contact 110 a simple circuit for a re verse indicatingdevice 6R. Half-wave rectifiers 111 and 112 may be connected across thetop windings of relays BNKP and SRKP, respectively, to provide theserelays with a slow releasing characteristic; 7 a

In a similar manner, the indicating relays TNKP and 'YRKP for the pushbutton '7PB each have one terminal of their top winding connect eddirectly with the common line wire Com, at the terminal 0; the otherterminal of the top winding of relay TINKP being connected with the linewire L over a loop circuit including a halfwave rectifier 113, backcontact 114 of relay TPBE, back contacts and 81 of the stick re,, laysSPBS and QPBS, respectively, and the front contact 82 of the stick relay'7PBS. The other terminal of'the top winding of relay 'lRKP is connectedwith the line wire L over a loop cir-. cult including a half -Waverectifier 115, back contact 114, and thence by the circuit just tracedfor the relay 'YNKP. Rectifiers 113 and115 have their forward directionsreverse to eachqother and are so arranged that an impulse flowing fromthe common line wire toward the line wire L. will energize the relay'YRKP, and an impulse flowing from the line wire L toward the commonline wire Com, will energize the relay 'YNKP. Again, it is to be notedthat after the control relay '7PBR associated with push button 7PBreleases to terminate an outgoing control impudse, the as sociated stickrelay 739138 is retained energized to connect the two indicating loopcircuits for the push button IP13 with the line circuit. Relay 'INK?once picked up, it will be retained,.ener-' gized by stick circuit thatincludes the back contact 116 of the control relay 7PBR, its own frontcontact 117,. and its lower .winding Relay 'YRKP once picked up it willbe retained energized by a stick circuit that includes the back con-:tact 116, its own front contact l18and its lower winding. Relays UNKE:and 'lRKP control at theirrespective front contacts 119 and 120,, nor,-mal and reverse indicating devices 7N and IR.

Again, the indicating relays QNKP and BRKP for the push button 91 B eachhave one terminal of their top winding connected with the common l'newire at the terminal C; the opposite terminal of the top winding ofrelay QNKPbeing connected with the line wire L over a loopcircuit thatincludes a half-wave rectifier, 121-, back contact 122 of the associatedcontrol relay QPBR, back contacts and 9103 the stick relays GPBS and'YPBS, respectively, and the front contact 92 of .theassociatedstickrelay QPBS; and the other terminal of the top vwinding of relay QRKPbeing connected with the line wire L over a loop circuit "lat includes ahalf-wave rectifier 123 and the circuit just traced above...Consequently, as soon as therelay QPBR releases to terminate an outgoingcontrol impulse, the stick relay QPBS connects the two associated loopcircuits with the line circuit, the rectifiers121 and 123 being soarranged that one loop circuit will pass current of onepolarity andtheother loop. circuit will pass current ofthe opposite polarity- A stickcircuit Y for the relay- QNKP iseasily traced from the B terminal ofbattery 45 over back contact 124 of relay QPBR, frontcontact 125, andlower winding of that relay; and a stickcircuit for the relay QRKPincludes back contact 124, its own front contact 126, and its lowerwinding. These two relays QNKP and QRKP control at theirrespecvtivefront contacts 127 and 128 the normal and reverse indicating devicesQNand i llft. It clear from'the foregoing descriptionof the indicatingloop circuits associated with each push button that when apushbutton isoperated to initiate a control impulse, the associated stick relay isretamed energized to connect the associated loop circuits withthe linecircuit after the control impulse hasbeen terminated, one; loop circuitbeing arranged to respond to current of one polarity and the other loopcircuit being arranged to respond to current of the opposite polarity.When an indicating relay has oncebeen selected by an indicating impulse,that relay is retained energized by a local stick circuit tocontinuously energize a. corresponding indicating device.

Referring now to Fig. 2, a current impulse for indicating the positionof a switch is governed jointly-by the associated switch controlledrelay KR and the associatedswitch controlling r'elay WR. In mycopending. application Serial No. 631,041, it is described in detail howatlthe com} pletion of a movement of a railway. switch, the switchcontrolled relay KR is energizedin a cor: responding position, and asthe KRj rel'ayfis picked up,-current is removed from the switchcontrolling relayWR and the winding of that re lay is short-circuited togive that relay a slow re; lease acti,on. For example, 'r'riovement, ofthe switch 6 causes the controlled relay GKR t'obe energized in thecorresponding position'and the controlling relay GWR to be deenergizedand released with a slow release action. 'During' the slow" releaseperiod of the relay SWR, an indicat-' ing impulse is supplied tothefline circuit, the polarity of which is determined by the position ofthe GKR relay. With the switch 6 in itsreverse position and the GKRrelay in its reverse energized position, a c'onnectionf'is completedfrom the N terminal of field battery22 over the polar armature 129 ofrelay GKR, front contact 130 of relay 6KR,front contact 131 of relayfiWR, i and the front contacts 94and20' of thetwotrack relays 8TB and GTR,respectively, and to the line wire L. In the event the switch 6 is movedto its normal position then this connection extends from the B terminalof battery 22 over polar armature 129, front contacts 130, 131, 94 and20 to the line wire L. In other words, the reverse indicating impulsefor the switch 6 will flow from the battery 22 at the field station overthe common line wire Com to the o-ffice station through a correspondingloop circuit, and thence back over the line wire L to the N terminal ofbattery 22, and the normal indicating impulse for switch 6 will flowfrom the B terminal of battery 22 over the line wire L to the ofiicestation through a corresponding loop circuit, and back over the commonline wire Com to the C terminal of battery 22. Operating switch '7 toits reverse position and the subsequent energization of the 7KR relay inits reverse position completes a connection from the N terminal ofbattery 22 over the reverse position of polar armature 132 of relay ?KR,front contact 133, front contact 134 of the switch controlling relay'IWR, back contact 95, and front contacts 94 and 20 to the line wire L.Moving the switch '7 to its normal position and the subsequentenergization of the 'YKR relay in its normal position completes aconnection-from the B terminal of battery 22 to the line wire L over thesame circuit just traced above. In like manner, the polar armature 135of the switch controlled relay 9KR for switch 9, its front contact 136,and the front contact 137 oi. the switch controlling relay SWR. functionto complete a connection from either the B or N terminal of battery 22to the line wire L immediately following a movement of the switch 9. Itis clear, therefore, that an impulse of current of negative polarity issupplied to the line circuit subsequent to an operation of switch 6, '7or 9 to the reverse position, and an impulse of current of positivepolarity is supplied to the line circuit subsequent to an operation ofswitch 6, l or 9 to the normal position, the duration of each impulsebeing equal to the release period of the asare pickedup over theirenergizing circuits.

sociated switch controlling relay.

In describing the operation of the system as a whole, I shall firstassume that the switches 6, 7 and 9, and their respective control relaysoccupy the normal position, that is, the position illustrated in thedrawings. I shall further assume that the track circuits for the tracksections 6'1 and ST are both unoccupied, and also that the normalindicating relay NKP for each push button is energized. I shall nextassume that the 55' dispatcher desires to move the switch 6 and hencedepress the push button 6PB for an interval and then release it. Whenthe push button GPB is depressed, the two control relays SPBR and 6PBSRelay SPBR in picking up opens the back contact 106 to deenergize theindicating relay'6NKP and that relay releases to extinguish theindicating device 6N, and to complete the stick circuit for the relay6PBS at the back contact 54. As the pushbutton GPB is restored to itsnormal position, current is removed from the relay GPBR and that relayreleases at the end of its slow release period, but the stick relay 6PBSremains energized over its stick circuit. During the interval thatrelays SPBR and GPBS are both up, a control impulse of current ofpositive polarity is supplied to the line circuit and the relay LGR ofthe field station is energized. Relay LGR, in

., turn, completes the circuit to the controlling relays for the switchmechanism 6M, and these relays then function to bring about theoperation of the switch 6 to its reverse position. When the relay 6PBRis released, the loop circuits for the push button 6PB are connected tothe line wires, the connection being completed at the back con tact 104.As soon as the switch 6 is fully reversed, and the SKR relay isenergized in its reverse position; an indicating impulse of current ofnegative polarity is supplied to the line wires duringthe release periodof relay 6W3, and this indicating impulse is passed by the rectifier 185and the indicating relay GRKP is energized and then retained energizedby its local stick circuit. Relay GRKP upon picking up, causes thedisplay of the reverse indicating device GR, and opens the stick circuitto the relay SPBS at the back contact 55, and that relay is dcenergized.It is to be noted that the stick relay 6PBS is retained picked up untilthe indication is completed, and that as long as the relay SPBS ispicked up the back contacts 58 and are open and the push button PE isrendered ineffective; and, also, the back contacts 69 and are open torender the push button 9PB ineffective. In other Words, operating thepush button 6P3 locks out the remaining two push buttons until theoperation initiated by the push button BPB has been fully completed andindicated.

I shall now assume that the dispatcher desires to return the switch 6 toits normal position. By operating the push button 6P3 the second time,the relays GPBR and 6PBS are picked up over their energizing circuit thesame as before, and the indicating relay SRKP is released to eittinguishthe indicator GR, and to complete the stick circuit for relay 6PBS. Thecontrol impulse supplied to the line wires again selects the relay LGR,but this time the relay 6RWR of the control group is selected as thepolar armature 21 is in the reverse position and hence the switch 6 isoperated to its normal position. When the relay 6KR is picked up in itsnormal position at the completion of the movement of switch 6, anindicating impulse of current of positive polarity is supplied to theline wires and this impulse will pass through the rectifier 103 toenergize the normal indicating relay SNKP, and that relay in turnestablishes the normal indicator 6N and opens the stick circuit forrelay 6PBS at the back contact 54. 'Again it is to be noted that thestick relay GPBS is retained energized until the operation is fullycompleted and that as long as that relay is energized, the push buttons7P3 and 91 B are rendered ineifective.

To bring about an operation of the switch 7, the dispatcher will depressthe push button 71 B for a brief interval and then release it. Thecontrol relays '7PBR and 'lPBS will be picked up over their energizingcircuits to deenergize the associated indicating relays, and to supply acontrol impulse to the line wires. The control impulse this time will becurrent of negative polarity and the relay RGR will be selected which inturn, completes the circuit to the control relays for the switchmechanism 7M. Relay 'ZWR of this control group being in its normalposition, the switch '7 will be moved to its reverse position, afterwhich the IKE. relay will. be energized in its reverse position and anindicating impulse of current of negative polarity will be supplied tothe line wires. Relay TPBR having released in the meantime, thisindicating impulse will be passed by the rectifier 115 and indicatingrelay 'lRKP energized to establish the reverse indicating device IR, andto deenergize the l lll stick relay 'IPBS. It-will be noted that thestick relay TPBS When energized Tenders the push button 6PB ineffectiveby opening of the back cone tacts 51 and 76, and renders the push button9PB ineffective by opening the back contacts 68 and 91. Operating thepush button 'YPB the second time will cause the relays 'ZPBR and 'ZPBSto be energized in the manner described for the first operation of pushbutton 'YPB; and a control impulse will be supplied to the line wires toselect the relay RGR, and in-turn, select the'control relays formechanism 7M. Polar armature 32 now being in its reverse position, relay'lWR will be energized in its normal position and the switch 7 will beoperated-to its normal position and an indicating impulseof current ofpositive polarity will be supplied to the line wires which impulse willselect the indicating relay 'YNKP to establish the normal indicator 7N,and to deenergize the stick relay 'lPBS.

To effect a movement of the switch 9, the dispatcher will depress thepush button -9PB to energize the control relays QPBR and QPBS. RelayQPBR. when energized not only opens the stick circuit for the associatedindicating relay at the back contact 124, but also completes the circuitat the front contact 85 from operating the two relays 83 and 84 which,in turn will cause control impulses alternate in polarity to be suppliedto the line wires as long as the relay QPBR remains picked up. Therelays 83 and 84 are so proportioned as to operate faster than therelays LGR. and RGR, and consequently, the control impulses alternate inpolarity will cause the two relays LGR and RGR to be simultaneouslyenergized. With both relays LGR and RGR picked up at the same time, thecontrol relays for the switch mechanism 9M will be selected and theswitch 9 will. be operated. In the event the switch 9 is moved to itsreverse position, the

indicating impulse will be current'of negative.

polarity to select the indicating relay QRKP to establish the reverseindicator 9B. In the event the switch 9 is moved to its normal position,the indicating impulse will be current of positive polarity, and therelay QNKP will be selected to establish the normal indicator 9N. Againit will be noted that as long as the stick relay QPBS is picked up, thepush button SPB will be rendered inefiective by the opening of the backcontacts 50 and 7'7; and the push button 'IPB will be renderedineffective by the opening of the back contacts 59 and 81..

It is clear from the foregoing description of the operation of theswitches 6, 7 and 9 that the control impulses are supplied to the linecircuit for only a brief interval; and that the return indicatingimpulses also last only for a brief interval, the line circuit beingidle the remaining portion of the time. This being true, Ipropose toutilize the line circuit for OS-ing the occupancy of track sections inthe vicinity of the switches. Assuming a train enters the track sectionST and shunts the track'relay 6TB to deenergize that relay. When relay6TB releases, the closing of its back contact l38 cornpletes aconnection from the B terminal of the battery 22 to the line wire L andcurrent flows from the B terminal of battery 22 through back contact 38,line wire L, back contacts 139, 14c and '141 of the stick relays QBPS,'YBPS and GBPS, respec tively, half-wave rectifier 143,",winding'oi therelay SOSR to the C battery terminal at the office station, and thenceover the common line wire Com' to the C battery terminal at thefieldstation; Relay 608R is :now picked up'and-com- =pletes a simplecircuit'at its front contact 144 to an indicating light 6TL.- It followsthat the light fiTLis displayed to indicate the occupancy of the tracksection 6T as 'longas the track relay 6TR remains down. In the event thetrain enters the track section 8T and shunts the track relay 8TB, theclosing of its back-contact 145 completes a connection from the Nterminal of battery 22 to theline wire L, andcurrent flows from the 0battery terminal at the field station over the-commonline wire Comto-theC battery terminal at the oflice-station, through winding of relay8OSR,-rectifier 147, back contacts 141,140 and 139, and line wire L tothe N terminal of battery-22 through the back contact 145. Relay SOSR inpicking upcompletes at its front contact l48,"a simple circuit to thelight 8TL, and hence thislight 8TL is displayed to indicate theoccupancy 'of the track section 8T. It is to be noted that as long aseither relay GOSR 01" 808R isenergized and either back contact46 or- 47open the push buttons are. ineffective to initiate a controlimpulse. 1

'A control "system such as here disclosed pro-- vides for governing theoperation of at least-three railway-switches over a single pair of linewires by'simple and reliable apparatus; the line circuit at the sametime being availablefor' OS-ing track sections in the vicinity of theswitches.

Although I have herein shown and described only one form of apparatusembodying my inven" tion, it is understoodthat various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is: a

1. A control system for railway switches ineluding, a plurality ofrailway-switches at one point, a manually operated circuit controllerfor each railway 'switch and located at a second point, a slow releasecontrol relay anda'stick control relay for each circuit controller andboth normally deenergized,'means effective upon' operating a circuitcontroller to an active position to energizeits control relays, a stickcircuit for each stick relay for retaining the relay energized after thecircuit controller is restored to an inactive position, means controlledby each stick relay when energized for rendering each of the remainingcircuit controllers inefiective to energize its control relays, controlmeans eiiective to supply a control impulse during the release period ofthe slow release relay for establishing an operation of thecorresponding switch, an indication means for each circuit controller,an indication means for each switch adapted to supply an indicatingimpulse in response to each operation of "the switch for influencing thecorresponding'indication means, and means governed by each indicationmeans for opening the stick circuit of the associated stick relay inresponse to an indicating impulse and thereby restore the control ofeach of the circuit controllers over its control relays. a I

2. A control system for railway switches including, aplurality' ofrailway switches at one point, a manually operable circuit controllerfor each railway switchand locatedat a second point, a pair of linewires-extending etween said two points, a control means and anormallydecner gized stick relay for each circuit controller, means efifectiveupon operating a circuit controller to an active position for energizingits stick relay and for rendering its control means active to supply acontrol impulse to the line wires for effecting an operation of thecorresponding switch, a stick circuit for each stick relay for retainingthe relay energized after the circuit controller is restored to aninactive position, means controlled by each stick relay when energizedfor rendering each of the remaining circuit controllers ineffective togovern its control means, an indication means for each circuitcontroller governed by the control means and arranged to be connectedwith the line wires at the termination of a control impulse, anindication means for each switch adapted to supply to the'line wires anindicating impulse'in response to an operation of the switch forinfluencing the corresponding indication means, and means governed byeach indication means for opening the stick circuit of the associatedstick relay in response to an indicating impulse *whereby the control ofeach of the other circuit controllers over its control means isrestored.

3. A control system for railway switches including, a plurality ofrailway switches located at one point, a push button for each of saidrailway switches and located at a second point, a pair of f line wiresextending between said two'points, a

slow release control relay and a stick control relay for each pushbutton and both normally deenergized, means effective upon operation ofa push button for energizing its control relays, a stick circuit foreach stick relay for retaining the relay energized after the push buttonis released, means controlled by each stick relay when energized forrendering each of the other push buttons ineffective to energize itscontrol relays, control means effective to supply a control impulseduring the release period of the slow release relay to the line wiresfor effecting an operation of the corresponding switch, an indicationcircuit means for each push button and connected with said line wireswhen its stick relay is energized, an indication; means for each switchadapted to supply an indicating impulse to the line wires in response toeach operation of the switch for influencing the indication circuitmeans, and means governed by each indication circuit means for openingthe stick circuit of the associated stick relay in response to anindicating impulse.

4. A control system for railway switches including, a plurality ofrailway switches located at one point, a push button for each of saidswitches and located at a second point, a pair of 'line wires extendingbetween said two points, a control means for each push button renderedactive in response *to an operation of the push button to supply acontrol impulse to the line wires for effecting an operation of thecorresponding switch, a relay for each push button adapted to beenergized in response to an operation of the push button, a stickcircuit for each relay for retaining the relay energized afterthe pushbutton is released," means controlled by each relay 'when energized forrendering each of the remaining push buttons ineffective to govern itscontrol means, an indication means for each push button governed by thecontrol means and arranged to be connected with the line wires at thetermination of a control impulse, an indication means for each switchadapted to supply to the line wires an indicating impulse in response toan operation of the switch for influencing the corresponding indicationmeans, and means governed by each indication means for opening the stickcircuit of the associated relay in response to an indicating impulse.

5. A control system=for railway switches includ ing, a plurality ofrailway switches located at one point, a push button for each of saidswitches and located at a second point, a pair of line wiresextending"between said two points, a control means for each push buttonrendered active in response to an operation of the push button to supplyacontrol impulse to the line wires for effecting an operation of thecorresponding switch, a relay for each push button adapted to beenergized in response to an operation of the push button, a stickcircuit for each relay for retaining the relay energized after the pushbutton is released, means controlled by each relay when energized forrendering each of the remaining push buttons ineffective to govern itscontrol means, an indication means for each push button controlledjointly by the contrel means and the relay and arranged to be connectedwith the line wires at the termination of a control impulse only if saidrelay is energized, an indication means for each switch adapted tosupply to the line wires an indicating impulse in response to anoperation of the switch for influencing the indication means, and meansgoverned by each indication means for opening the stick circuit of theassociated relay in response to an indicating impulse.

6. A control system for railway switches including, a plurality ofrailway switches located at one point, a push button foleach of saidrailway switches and located at a second point, a pair of line wiresextending between said two points, a pair of loop circuits for each pushbutton each adapted to pass current in one direction only and arrangedto receive current from said line wires but normally disconnected,control means effective upon operation of a push button to supply acontrol impulse of a given duration to said line wires forei-fectingoperation of the corresponding switch, means governed by saidcontrol means to automatically connect the loop circuits of the operatedpush button with said line wiresat the expiration of the controlimpulse, indication means for each switch effective upon operation ofthe switch to supply to said line wires an impulse of current ofpositive or negative polarity according to the position of the switchfor influencing the loop circuits of the associated push button, and anormal and a reverse indication means selectively overned by the loopcircuits. 7

7. A control system for railway switches including, a plurality ofrailway switches located at one point, a push button for each or" saidrailway switches and located at a second point,,a pair of line wiresextending between said two points, a

pair of loop circuits for each push button each adapted to pass currentin one direction only and arranged to receive current from said 'linewires but normally disconnected, a slow release control relay and astick control relay for each push button and both normally deenergized,means effective upon operation of a push button to energize its twocontrol relays, control means governed by said relays for supplying tothe line wires a control impulse during the release period of theslow:release relay for effecting an operation of the correspondingswitch, means governed by said two relays for connecting the associatedloop circuits with the line wires at the expiration of said controlimpulse, indication means for each switch efieotive upon operation ofthe switch to supply to said line wires for a given interval an impulseof current of positive or negative polarity according to the position ofthe switch for influencing the loop circuits of the associated pushbutton, a

govern the operation second point, a pair by each switchqwhen line wiresan impulseof current oteither positive normal and a reverse indicatingrelay for each push buttonand selectively controlled by itsloopcircuits, and means governed by said indicating relays for indicatingthe position of the switch and for controlling the stickcircuit of theassociated stick relay. l 1 k 8. A control system for railway switchesincluding, a plurality of railway switches located at one point, a pushbutton for each of said railway switches andlocated' at asecondpointfapair of line wires extending between said two points,- a pair of loopcircuits for each pushbutton each adapted to pass current in onedirection only and arranged to receive current fr ords'aid line wiresbut normally disconnected, a slow release control relay and astickcontrol, relay for each push button and both normally deenergized, meanseffective upon operation of a push'button to energize itstwo controlrelays, a stick circuit for retaining the stick relay energizedafter thepush button is released, meansgoverned by each stick relay whenenergized for rendering each of the remaining push buttons ineffectiveto ener gize its control relays, a control means effective to supply tothe line wires a control impulse'during the release period of the slowrelease relay for effecting an operation of the corresponding switch,circuit means completed with the slowre: lease relay down and thejstickrelay picked up for connecting the associated loop circuits with theline wires, indication means" for each switch effective upon operationof the switchto supply to the line wires an impulse of current ofpositive or negative polarity according to the position of the switchfor influencing the loop circuits of the associated push button, anormal andfa're'verse indicating relay for each push button selectivelycontrolled by its loop circuits, a normal and a reverse indicatorselectively governed by the indi cating relay, and means governed bysaid indicating relays for controllingthe. stick circuitof theassociated stick relay whereby 'e'achofthe remaining push buttonsis,a'gain ;renderedjefiective to energize its control relaysl'at thecompletion of the indication.

9. A control system for railway switches including, two switchcontrolling means locate'd'at one point and each adapted'when"energized" to of a corresponding switch, button for each switch andlocated ata of line wires'extending between said one point andsaid"second point, a pair of loop circuits at said one point normallyconnected with the line wires and. each'adapted to pass currentin onedirection, only,.mea n's controlled by said loop circuits forselectively energizing the switch controlling means, a pair of loopcircuits for each push button normally disconnected from said line wiresandfeach adaptedto pass current in one directiononlyf control meansefiective upon operation of a .first push button to supply a controlimpulse ofcurrent of positive polarity to said line wires forinfluencingthe cor:- responding loop circuit at said one point to causea push operation of the corresponding switch, and effective uponoperation of the second push button to supply a control impulse ofcurrent ofnegative polarity for influencing the other loop circuitatsaid one point to cause operation of the other switch; means governed bysaid control means to connect the loop circuits for the operated pushbutton with the line wires, and means governed operated to supply tosaid or negative polarity according to, the, position, of

said switohfor influencing the corresponding loop circuit of 'theoperated push butt on for'indicating thelp'osition of saidswitch. f w r10; A' control. systeni'for' railway switches ineluding, 'three' switchcontrolling devices located at onef point and each adapted to govern theoperation era correspondingy'switch and to at times supply 'anindic'ating'cur'rent, three manually ioperated' levers located at 'asecond point, an indication means 'for each lever, a single line circuitconnecting said two points, a pair of loop circuits connected with theline" circuit at said o'ne'point'and each including a relay and ahalfwave rectifierfwith the rectifiers arranged in reversedirections,means effective to control one of the switch controlling 'devices whenone of said relays is energized, to control a second one of the switchcontrolling devices when the other of said relays is energized and tocontrol the third switch controlling devices when both relays aresimultaneously energized; a current source rendered effective to supplycurrent of one polarity to the line pir'cuit when one, of said levers"is operated, 'tc'suppl'y current, of opposite polarity when a secondone'of said levers is operatedand to supply impulses ofjcurrnt'alternatein polarity'when the third lever is operated, andlmeans governed by eachleverwhen operated'to render the other levers inefiective tov governsaid current source and to" automatically connect the correspondingindication means with said line circuit'to receive the indicatingcurrent from the selected switch controlling device.

l ci'rcuits' connected with the line circuit at said one point andeachjincluding a relay and a halfwaverectifi'er with the, rectifiersarranged in re- 1 lversedirectionsg means effective to control one oftheswit hcontrollingfdevices when one of said relays "is energized, tocontrol} a second one of the switch,controlling devices when the otherof said relays is energizedand to control the third switch controllingdevices'when both relays are simuljeffecti've to supply an impulse ofcurrent of one polarity to the line circuit when one of said levers i pat V to supply an impulse of current of opposite'p'ol rit'y whena secondone of said levers is operated and to supply impulses of currentalternate in polarity when the third lever is operated; means governedby each lever when oper- "ated to render the "other levers ineffectiveto govern said'current source and to automatically connect thecorresponding indication means with said line' circuit to receive'theindicating current from the: selected switch controlling device, and

means controlled by each indication means to restore the controlof theother levers over the .currentsource in response to the indicating cur-.rent.;. :v ,l v

, 12, A control systemfor railway switches including, two switchoperating devices located the, operation of a corresponding switch andto supply at timesran' indicating current impulse in accordance'with theposition of the switch, two -manually: operated levers located at asecond ;.poi nt-, an indicationmeans: for each lever, a pair 150taneouslyenergized; 'a'curren't source rendered "at; one point-andyeachadapted to govern of line wires extending between the two points, a pairof loop circuits connected with said line wires at said one point andeach including a relay and a half-wave rectifier with the rectifiersarranged reverse to each other, means effective to control one of theswitch operating devices when one of the relays is energized and tocontrol the other switch operating device when the other relay isenergized, means effective to supply a control impulse of current ofpositive polarity to the line wires when one of the levers is operatedand to supply a control impulse of current of negative polarity when thesecond lever is operated to selectively energize the relays of said loopcircuits, means governed by each lever when operated to render the otherlever ineffective and to automatically connect the correspondingindication means with the line wires at the end of the control impulseto receive the indicating current impulse of the selected switchcontrolling device, and means governed by each indication means toindicate the position of the switch and to restore the other lever toits'effective condition.

13. A control system for railway switches including, a railway switch atone point, a manually operated circuit controller normally occupying aninactive position and located at a second point, a pair of line wiresextending between the two points, circuit means connected with the linewires at said one point and responsive to a current impulse forefiecting an operation of said switch, a slow release control relay anda stick control relay at said second point and normally deenergiz'ed,means for energizing said control relays in response to operating the,circuit controller to an active position, a stick circuit for said stickrelay to retain said relay energized after the circuit controller isrestored to itsiinactive position, control means controlled jointly bysaid two control relays and arranged to, supply a control impulse to theline wires during the release period of said slow release relay forenergizing the circuit means at said one point,'indication meanscomprising two loop circuits each including a half-wave rectifier and arelay and adapted to receive current from the linewires'but normallydisconnected,indication means governed by the switch whenoperated tosupply to the line wires an indicating impulse of current of eitherpositive or negative polarity according to the position of the switch,means controlled by the stick relay when energized to connect theindication means with the line wires at'the expiration of the controlimpulse, and means controlled by the relays of the indication means toindicate the position of the switch and to open the stick circuit inresponse to an indicating impulse.

14. A control system for railways including, two railway switches andtwo track sections at one point, a track circuit including a track relayfor each track section, an-operatingmeans for each switch, a manuallyoperated circuit controller for each switch and located at a secondpoint, an indicator for each track section and located at thesecondpoint, a pair of line wires extending between the two points, twoloop circuits normally connected with the line wires at the said'onepoint and each including a half-wave rectifier and a relay, two loopcircuits normally connected with the line wires at said second point andeach including a half-wave rectifier and a relay, means controlled bythe relays of the loop circuits at said one point to selectively governthe two operating means, means controlled by the relays of the loopcircuits at said second point to'h'selec; tively govern the'twoindicators, means ei fective when one of the circuit controllers isoperated to supply to the line wires an impulse of current of one trackrelay is shunted to supply to the line wires current of positivepolarity to energize the loop circuit at said second'point to controlone indicator, means effective when the other track relay is shunted tosupply to the line wires current of negative polarity to energize theother loop circuit at the second point to control the other indicator,means eiiective when either circuit controller is operated to disconnectthe loop circuits at said second point, andmeanseffective when eithertrack relay is shunted to disconnect the loop circuits at said onepoint.

15. A control system for railways including,a railway switch and a tracksection at one point, a track circuit including a track relay for thetrack section, an operating means for moving the switch, a manuallyoperated circuit controller at a second point; a normal and a reverseswitch indicator and a; track indicator at said second point; a'pair ofline Wires extending between said two points, a loop circuit normallyconnected with the line wires at said one point for controlling theoperating means; an indication means for controlling saidswitchindicators and comprising two loop circuits each including a half-waverectifier and a relay, and adapted to receive current from the linewires but normally disconnected; a third loop circuit at saidsecondjpoint for controlling the track indicator and normally connectedwith the line wires, control means effective in response to an operationof the circuit controller to disconnect said third loop circuit and tosupply to the line wiresa control impulse to energize the loop circuitat said one point to operate'the switch; means governed by the controlmeans to connect the indication means with said line wires at thetermination of the control impulse, indication means governedby theswitch when operated to supply .to the, line wires an indicating impulseof current'of either positive or negative polarity according to theposition'of the switch to influence the corresponding loop circuit ofthe indication means to establish the corresponding switch indicator,and means effective when the track relay is shunted to disconnect theloop circuit at said one point and to supply to the line wires currentto energize said third loop circuit to establish the track indicator.

16. A control system for railways including, a I

railway switch and a track section at one point, a track circuitincluding a, track relay for the track section, a manually operatedcircuit controller at a second point, a pair of line wires eX- tendingbetween said two points, an operating means normally connected with theline wires at said one point and adapted to effect an operation of saidswitch in response to an impulse of current, an indication meansnormally connected with the line wires at said second point and adaptedwhen energized to display an indication, control means at said secondpoint to supply to the line wires a control impulse of current inresponse to an operation of said circuit controller to influence theoperating means, means governed wires current for energizing theindication means to indicate at said second point the occupancy of thetrack section, and means governed by the indication means when energizedto render the control means inefi'ective.

PAUL H. CRAGO.

